Microfluidic separation device

Abstract

A microfluidic separation device is provided that includes a sample channel having a first sample channel region and a second sample channel region, where a cross-section of the first sample channel region is smaller than a cross-section of the second sample channel region. The invention further includes a detection region having a first detection region and a second detection region, where a cross-section of the first detection region is larger than a cross-section of the second detection region and the second sample channel region is connected to the first detection region. Additionally, the invention includes a marker input channel disposed to input markers into the second sample channel region, where the markers are larger than the cross-section of the first sample channel region and the cross-section of the second detection region, where the markers collect in the first detection region.

What is claimed is: 
     
       1. A microfluidic separation device comprising:
 a. a sample channel, wherein said sample channel comprises a first sample channel region and a second sample channel region, wherein a cross-section of said first sample channel region is smaller than a cross-section of said second sample channel region; 
 b. a detection region comprising a first detection region and a second detection region, wherein a cross-section of said first detection region is larger than a cross-section of said second detection region and said second sample channel region is connected to said first detection region; 
 c. an illuminating electric field; 
 d. Raman-scattering nanoparticles, wherein said Raman-scattering nanoparticles comprise surface plasmon resonances for detection when illuminated by said illuminating electric field, wherein said surface plasmon resonances create an enhanced local electric field along specific directions, wherein said enhanced local electric field results in an enhanced Raman response; and 
 e. a Raman nanoparticle input channel disposed to input said Raman-scattering nanoparticles into said second sample channel region, wherein said Raman-scattering nanoparticles are larger than said cross-section of said first sample channel region and larger than said cross-section of said second detection region, wherein said Raman-scattering nanoparticles are disposed to collect in said first detection region to form region of densely packed said Raman-scattering nanoparticles. 
 
     
     
       2. The microfluidic separation system of  claim 1 , wherein said Raman-scattering nanoparticles have a size in a range of 10 nm to 10 μm. 
     
     
       3. The microfluidic separation system of  claim 1 , wherein said Raman-scattering nanoparticles move when subject to forces selected from the group consisting of electroosmosis, electrophoresis, fluid pressure, moveable wall pressure, undulary electroosmosis, undulary electrophoresis, undulary fluid pressure and undulary moveable wall pressure. 
     
     
       4. The microfluidic separation system of  claim 1 , wherein said Raman-scattering nanoparticles are selected from the group consisting of gold particles, copper particles, silver particles, magnetic particles, particles having binding chemistry, and quantum dots. 
     
     
       5. The microfluidic separation system of  claim 1 , wherein said second detection region comprises a sieve structure having openings smaller than said Raman-scattering nanoparticles. 
     
     
       6. The microfluidic separation system of  claim 1 , wherein said detection region comprises flexible material, wherein said flexible material is operably disposed to form said first sample channel region and said second detection channel region.